This is the most important advice we can give, and it applies to coins, currency, jewelry, and most collectibles:
Do not try to clean or “improve” them.
It’s completely understandable. You may see a similar coin online that looks brighter or more polished and assume a little cleaning will increase the value. In reality, the opposite is almost always true.
Cleaning can permanently damage a coin.
Even light cleaning can remove original surfaces that collectors and professionals rely on to determine authenticity and condition. Once those surfaces are altered, the value can drop significantly — sometimes to a fraction of what it was.
We’ve seen this happen many times. In one case, a client had an 1884-S Morgan dollar in about-uncirculated condition, worth several thousand dollars. After using a commercial coin cleaning product, it was reduced to little more than its silver value.
Handling can also cause damage.
Something as simple as a fingerprint can affect the surface of a coin, especially proof coins with mirror-like finishes. Oils from your skin can leave marks that are difficult or impossible to reverse.
The best approach is simple:
- Leave everything exactly as you found it
- Avoid unnecessary handling
- Keep items in their original holders or containers
If something needs conservation, it should be done by professionals with the proper training and materials.
If you’re unsure about anything you have, it’s always better to ask before taking action. A quick look can prevent a costly mistake.
If you’d like help understanding your collection or preparing items for appraisal or sale, we’re always available.
And if you’d like more guidance like this, we encourage you to join our mailing list as we continue adding new posts.
— Marc Alan Rosner
Hudson Valley Numismatics